Explanation:
The ghost of
a long-dead star,
the W63 supernova remnant shines
like a faint cosmic smoke-ring along the plane of the Milky Way
galaxy toward the northern
constellation Cygnus the swan.
Its wraithlike appearance is traced against the
region's rich complex of interstellar
clouds and dust by an eerie blue glow.
Spanning over four full moons on the sky,
the beautiful image
is a telescopic mosaic in twelve panels
that combines 100 hours of exposure time using narrow band filters.
It shows characteristic light from ionized atoms of sulfur, hydrogen and
oxygen in red, green, and blue hues.
Likely over 5,000 light-years away, the visible part of the
still expanding
shell supernova remnant is around 150 light-years in diameter.
So far no source has been identified as with
the remains
of W63's original star.
Light from the star's
supernova
explosion would have reached Earth over 15,000 years
ago.